code: def _check_if_model_is_unknown(
      equation: str, expression: str
  ) -> bool:
      if "->" in equation:
          if re.match(_UNKNOWN_MODEL_PATTERN, expression):
              return True
      return False
  
imports: import ast
  import logging
  import re
  from typing import Tuple
  import networkx
  import numpy
  import scipy.stats
  from dowhy.gcm import AdditiveNoiseModel, EmpiricalDistribution, ScipyDistribution, StructuralCausalModel
  from dowhy.gcm.causal_mechanisms import StochasticModel
  from dowhy.gcm.causal_models import PARENTS_DURING_FIT
  from dowhy.gcm.ml.prediction_model import PredictionModel
  from dowhy.gcm.util.general import shape_into_2d
  from dowhy.graph import get_ordered_predecessors
label_desc: Use image node_id 11 for calling a global function with example usage: _check_if_model_is_unknown(equation, expression) and returns: False, True